1000 resultados para Air pilots.


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The temperature of water in a river system affects fish in various ways; it has an influence on feeding habits, movement and metabolism. All fish vary in their ability to tolerate fluctuations in temperature, but those that live in a reasonably stable environment are more sensitive to major changes (tropical fish) than are salmon which can tolerate abrupt changes. The body temperature of the majority of fish differs from that of the surrounding water by only 0.5 to 1.0 degrees, and changes in temperature can, in many cases, be a signalling factor for some process, for example spawning, migration or feeding. It has been found, after monitoring the activity in 2,623 salmon in the River Lune, that they live in a water temperature of 0-17 degrees. Whilst salmon ova can develop in a temperature range of 0-12 degrees, spawning takes place within a much closer range, and these tolerances will be found in the Report. This report offers data and analysis of fish movement correlated to water temperature for the years 1964/65.

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225 p.

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While an overwhelming majority of sub-Saharan African countries exhibit serious weaknesses in statistics pertaining to crop and livestock sectors, the deficiencies in terms of nationally representative data on the fishery sector are even more acute. The very little data available on the sector are essentially derived from case studies of selected fisheries, and the limited nationally representative data available are generally derived from a few questions included in the livestock section of household surveys. These do not permit the detailed characterization of the fishery production systems. As a consequence in many countries the decision-makers and planners lack the most basic information about the role and importance of the fisheries sector to their national economy. As part of an initiative called the Living Standards Measurement Study-Integrated Surveys on Agriculture (LSMS-ISA) project, a collaboration was developed between the World Bank and the WorldFish Center to address this situation. This report provides detail on pilot testing of a fisheries module for living standards measurement surveys.

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